Methods, apparatuses and systems directed to proximity services (ProSe) direct discovery

ABSTRACT

Methods, apparatus, systems, devices, and computer program products directed to enhancements to proximity-based services (ProSe) direct discovery are provided. Among the methods is a method that may be implemented in a proximity services (ProSe) function and that may include receiving a discovery request message including a ProSe application identifier; determining whether or not the ProSe function can retrieve a valid ProSe application code corresponding to the ProSe application identifier; and transmitting a reject-type discovery response message conditioned on the determining that a valid ProSe application code is not available to the ProSe function.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 62/143,681 filed 6-Apr.-2015, and U.S. ProvisionalPatent Application Ser. No. 62/162,437 filed 15-May-2015, each of whichis incorporated herein by reference.

BACKGROUND

Field

The present disclosure relates generally to communications, and moreparticularly to proximity services.

Related Art

Proximity services (ProSe) enable network assisted discovery of users inclose physical proximity and facilitate direct communication betweenthose users, where and/or if appropriate. Direct communication involvesa radio connection established between the users' wireless communicationdevices without transiting via the network. ProSe may save networkresources, permit public safety communication when network coverage isunavailable, social networking, file transfer, and other servicesbetween devices.

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding may be had from the detailed descriptionbelow, given by way of example in conjunction with drawings appendedhereto. Figures in such drawings, like the detailed description, areexamples. As such, the Figures and the detailed description are not tobe considered limiting, and other equally effective examples arepossible and likely. Furthermore, like reference numerals (“ref.”) inthe Figures (“FIGs.”) indicate like elements, and wherein:

FIG. 1A is a system diagram of an example communications system in whichone or more disclosed embodiments may be implemented;

FIG. 1B is a system diagram of an example wireless transmit/receive unit(WTRU) that may be used within the communications system illustrated inFIG. 1A;

FIG. 1C is a system diagram of example radio access networks and examplecore networks that may be used within the communications systemillustrated in FIG. 1A;

FIG. 2 is a block diagram illustrating an example proximity service(ProSe) architecture;

FIG. 3 is a flow diagram illustrating an example ProSe Model B directdiscovery procedure;

FIG. 4 is a flow diagram illustrating an example procedure in accordancewith one or more embodiments;

FIG. 5 is a message flow diagram illustrating an example procedure forcarrying out an inter-ProSe function information transfer;

FIG. 6 is a message flow diagram illustrating an example metadatatransfer procedure;

FIG. 7 is a message flow diagram illustrating example procedures for usein connection with inter-ProSe function metadata transfer;

FIG. 8 is a message flow diagram illustrating example procedures for usein connection with inter-ProSe function metadata transfer;

FIG. 9 is message flow diagram illustrating example procedures for usein connection with inter-ProSe function metadata transfer;

FIG. 10 is message flow diagrams illustrating example procedures for usein connection with metadata transfer;

FIG. 11 is a message flow diagram illustrating an example procedure foruse in connection with metadata transfer;

FIG. 12 is a message flow diagram illustrating an example procedure foruse in connection with metadata transfer;

FIG. 13 is a message flow diagram illustrating an example procedure foruse in connection with metadata transfer;

FIG. 14 is a message flow diagram illustrating an example procedure foruse in connection with metadata transfer;

FIG. 15 is a message flow diagram illustrating an example procedure foruse in connection with requesting application controlled suffixinformation;

FIG. 16 is a message flow diagram illustrating an example procedure foruse in connection with requesting application controlled suffixinformation; and

FIG. 17 is a message flow diagram illustrating a Discoverer discoveryrequest procedure.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are setforth to provide a thorough understanding of embodiments and/or examplesdisclosed herein. However, it will be understood that such embodimentsand examples may be practiced without some or all of the specificdetails set forth herein. In other instances, well-known methods,procedures, components and circuits have not been described in detail,so as not to obscure the following description. Further, embodiments andexamples not specifically described herein may be practiced in lieu of,or in combination with, the embodiments and other examples described,disclosed or otherwise provided explicitly, implicitly and/or inherently(collectively “provided”) herein.

Example Communications System

The methods, apparatuses and systems provided herein are well-suited forcommunications involving both wired and wireless networks. Wirednetworks are well-known. An overview of various types of wirelessdevices and infrastructure is provided with respect to FIGS. 1A-1E,where various elements of the network may utilize, perform, be arrangedin accordance with and/or be adapted and/or configured for the methods,apparatuses and systems provided herein.

FIG. 1A is a diagram of an example communications system 100 in whichone or more disclosed embodiments may be implemented. The communicationssystem 100 may be a multiple access system that provides content, suchas voice, data, video, messaging, broadcast, etc., to multiple wirelessusers. The communications system 100 may enable multiple wireless usersto access such content through the sharing of system resources,including wireless bandwidth. For example, the communications systems100 may employ one or more channel access methods, such as code divisionmultiple access (CDMA), time division multiple access (TDMA), frequencydivision multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrierFDMA (SC-FDMA), and the like.

As shown in FIG. 1A, the communications system 100 may include wirelesstransmit/receive units (WTRUs) 102 a, 102 b, 102 c, 102 d, a radioaccess network (RAN) 104, a core network 106, a public switchedtelephone network (PSTN) 108, the Internet 110, and other networks 112,though it will be appreciated that the disclosed embodiments contemplateany number of WTRUs, base stations, networks, and/or network elements.Each of the WTRUs 102 a, 102 b, 102 c, 102 d may be any type of deviceconfigured to operate and/or communicate in a wireless environment. Byway of example, the WTRUs 102 a, 102 b, 102 c, 102 d may be configuredto transmit and/or receive wireless signals, and may include userequipment (UE), a mobile station, a fixed or mobile subscriber unit, apager, a cellular telephone, a personal digital assistant (PDA), asmartphone, a laptop, a netbook, a personal computer, a wireless sensor,consumer electronics, a terminal or like-type device capable ofreceiving and processing compressed video communications, or like-typedevice.

The communications systems 100 may also include a base station 114 a anda base station 114 b. Each of the base stations 114 a, 114 b may be anytype of device configured to wirelessly interface with at least one ofthe WTRUs 102 a, 102 b, 102 c, 102 d to facilitate access to one or morecommunication networks, such as the core network 106, the Internet 110,and/or the networks 112. By way of example, the base stations 114 a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a HomeNode B, a Home eNode B, a site controller, an access point (AP), awireless router, a media aware network element (MANE) and the like.While the base stations 114 a, 114 b are each depicted as a singleelement, it will be appreciated that the base stations 114 a, 114 b mayinclude any number of interconnected base stations and/or networkelements.

The base station 114 a may be part of the RAN 104, which may alsoinclude other base stations and/or network elements (not shown), such asa base station controller (BSC), a radio network controller (RNC), relaynodes, etc. The base station 114 a and/or the base station 114 b may beconfigured to transmit and/or receive wireless signals within aparticular geographic region, which may be referred to as a cell (notshown). The cell may further be divided into cell sectors. For example,the cell associated with the base station 114 a may be divided intothree sectors. Thus, in one embodiment, the base station 114 a mayinclude three transceivers, i.e., one for each sector of the cell. Inanother embodiment, the base station 114 a may employ multiple-inputmultiple-output (MIMO) technology and, therefore, may utilize multipletransceivers for each sector of the cell.

The base stations 114 a, 114 b may communicate with one or more of theWTRUs 102 a, 102 b, 102 c, 102 d over an air interface 116, which may beany suitable wireless communication link (e.g., radio frequency (RF),microwave, infrared (IR), ultraviolet (UV), visible light, etc.). Theair interface 116 may be established using any suitable radio accesstechnology (RAT).

More specifically, as noted above, the communications system 100 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 114 a in the RAN 104 and the WTRUs 102 a, 102b, 102 c may implement a radio technology such as Universal MobileTelecommunications System (UMTS) Terrestrial Radio Access (UTRA), whichmay establish the air interface 116 using wideband CDMA (WCDMA). WCDMAmay include communication protocols such as High-Speed Packet Access(HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-Speed DownlinkPacket Access (HSDPA) and/or High-Speed Uplink Packet Access (HSUPA).

In another embodiment, the base station 114 a and the WTRUs 102 a, 102b, 102 c may implement a radio technology such as Evolved UMTSTerrestrial Radio Access (E-UTRA), which may establish the air interface116 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A).

In other embodiments, the base station 114 a and the WTRUs 102 a, 102 b,102 c may implement radio technologies such as IEEE 802.16 (i.e.,Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000,CDMA2000 1×, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), InterimStandard 95 (IS-95), Interim Standard 856 (IS-856), Global System forMobile communications (GSM), Enhanced Data rates for GSM Evolution(EDGE), GSM EDGE (GERAN), and the like.

The base station 114 b in FIG. 1A may be a wireless router, Home Node B,Home eNode B, or access point, for example, and may utilize any suitableRAT for facilitating wireless connectivity in a localized area, such asa place of business, a home, a vehicle, a campus, and the like. In oneembodiment, the base station 114 b and the WTRUs 102 c, 102 d mayimplement a radio technology such as IEEE 802.11 to establish a wirelesslocal area network (WLAN). In another embodiment, the base station 114 band the WTRUs 102 c, 102 d may implement a radio technology such as IEEE802.15 to establish a wireless personal area network (WPAN). In yetanother embodiment, the base station 114 b and the WTRUs 102 c, 102 dmay utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE,LTE-A, etc.) to establish a picocell or femtocell. As shown in FIG. 1A,the base station 114 b may have a direct connection to the Internet 110.Thus, the base station 114 b may not be required to access the Internet110 via the core network 106.

The RAN 104 may be in communication with the core network 106, which maybe any type of network configured to provide voice, data, applications,and/or voice over internet protocol (VoIP) services to one or more ofthe WTRUs 102 a, 102 b, 102 c, 102 d. For example, the core network 106may provide call control, billing services, mobile location-basedservices, pre-paid calling, Internet connectivity, video distribution,etc., and/or perform high-level security functions, such as userauthentication. Although not shown in FIG. 1A, it will be appreciatedthat the RAN 104 and/or the core network 106 may be in direct orindirect communication with other RANs that employ the same RAT as theRAN 104 or a different RAT. For example, in addition to being connectedto the RAN 104, which may be utilizing an E-UTRA radio technology, thecore network 106 may also be in communication with another RAN (notshown) employing a GSM radio technology.

The core network 106 may also serve as a gateway for the WTRUs 102 a,102 b, 102 c, 102 d to access the PSTN 108, the Internet 110, and/orother networks 112. The PSTN 108 may include circuit-switched telephonenetworks that provide plain old telephone service (POTS). The Internet110 may include a global system of interconnected computer networks anddevices that use common communication protocols, such as thetransmission control protocol (TCP), user datagram protocol (UDP) andthe internet protocol (IP) in the TCP/IP internet protocol suite. Thenetworks 112 may include wired or wireless communications networks ownedand/or operated by other service providers. For example, the networks112 may include another core network connected to one or more RANs,which may employ the same RAT as the RAN 104 or a different RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities, i.e., theWTRUs 102 a, 102 b, 102 c, 102 d may include multiple transceivers forcommunicating with different wireless networks over different wirelesslinks. For example, the WTRU 102 c shown in FIG. 1A may be configured tocommunicate with the base station 114 a, which may employ acellular-based radio technology, and with the base station 114 b, whichmay employ an IEEE 802 radio technology.

FIG. 1B is a system diagram of an example WTRU 102. As shown in FIG. 1B,the WTRU 102 may include a processor 118, a transceiver 120, atransmit/receive element 122, a speaker/microphone 124, a keypad 126, adisplay/touchpad 128, non-removable memory 106, removable memory 132, apower source 134, a global positioning system (GPS) chipset 136, andother peripherals 138. It will be appreciated that the WTRU 102 mayinclude any sub-combination of the foregoing elements while remainingconsistent with an embodiment.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), agraphics processing unit (GPU), a plurality of microprocessors, one ormore microprocessors in association with a DSP core, a controller, amicrocontroller, Application Specific Integrated Circuits (ASICs), FieldProgrammable Gate Array (FPGAs) circuits, any other type of integratedcircuit (IC), a state machine, and the like. The processor 118 mayperform signal coding, data processing, power control, input/outputprocessing, and/or any other functionality that enables the WTRU 102 tooperate in a wireless environment. The processor 118 may be coupled tothe transceiver 120, which may be coupled to the transmit/receiveelement 122. While FIG. 1B depicts the processor 118 and the transceiver120 as separate components, it will be appreciated that the processor118 and the transceiver 120 may be integrated together in an electronicpackage or chip.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, thetransmit/receive element 122 may be an antenna configured to transmitand/or receive RF signals. In another embodiment, the transmit/receiveelement 122 may be an emitter/detector configured to transmit and/orreceive IR, UV, or visible light signals, for example. In yet anotherembodiment, the transmit/receive element 122 may be configured totransmit and receive both RF and light signals. It will be appreciatedthat the transmit/receive element 122 may be configured to transmitand/or receive any combination of wireless signals.

In addition, although the transmit/receive element 122 is depicted inFIG. 1B as a single element, the WTRU 102 may include any number oftransmit/receive elements 122. More specifically, the WTRU 102 mayemploy MIMO technology. Thus, in one embodiment, the WTRU 102 mayinclude two or more transmit/receive elements 122 (e.g., multipleantennas) for transmitting and receiving wireless signals over the airinterface 116.

The transceiver 120 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 122 and to demodulatethe signals that are received by the transmit/receive element 122. Asnoted above, the WTRU 102 may have multi-mode capabilities. Thus, thetransceiver 120 may include multiple transceivers for enabling the WTRU102 to communicate via multiple RATs, such as UTRA and IEEE 802.11, forexample.

The processor 118 of the WTRU 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, and/orthe display/touchpad 128 (e.g., a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit). The processor118 may also output user data to the speaker/microphone 124, the keypad126, and/or the display/touchpad 128. In addition, the processor 118 mayaccess information from, and store data in, any type of suitable memory,such as the non-removable memory 106 and/or the removable memory 132.The non-removable memory 106 may include random-access memory (RAM),read-only memory (ROM), a hard disk, or any other type of memory storagedevice. The removable memory 132 may include a subscriber identitymodule (SIM) card, a memory stick, a secure digital (SD) memory card,and the like. In other embodiments, the processor 118 may accessinformation from, and store data in, memory that is not physicallylocated on the WTRU 102, such as on a server or a home computer (notshown).

The processor 118 may receive power from the power source 134, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 102. The power source 134 may be any suitabledevice for powering the WTRU 102. For example, the power source 134 mayinclude one or more dry cell batteries (e.g., nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like.

The processor 118 may also be coupled to the GPS chipset 136, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the current location of the WTRU 102. In additionto, or in lieu of, the information from the GPS chipset 136, the WTRU102 may receive location information over the air interface 116 from abase station (e.g., base stations 114 a, 114 b) and/or determine itslocation based on the timing of the signals being received from two ormore nearby base stations. It will be appreciated that the WTRU 102 mayacquire location information by way of any suitablelocation-determination method while remaining consistent with anembodiment.

The processor 118 may further be coupled to other peripherals 138, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 138 may include anaccelerometer, an e-compass, a satellite transceiver, a digital camera(for photographs or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, and the like.

FIG. 1C is a system diagram of the RAN 104 and the core network 106according to an embodiment. As noted above, the RAN 104 may employ aUTRA radio technology to communicate with the WTRUs 102 a, 102 b, 102 cover the air interface 116. The RAN 104 may also be in communicationwith the core network 106. As shown in FIG. 1C, the RAN 104 may includeNode-Bs 140 a, 140 b, 140 c, which may each include one or moretransceivers for communicating with the WTRUs 102 a, 102 b, 102 c overthe air interface 116. The Node-Bs 140 a, 140 b, 140 c may each beassociated with a particular cell (not shown) within the RAN 104. TheRAN 104 may also include RNCs 142 a, 142 b. It will be appreciated thatthe RAN 104 may include any number of Node-Bs and RNCs while remainingconsistent with an embodiment.

As shown in FIG. 1C, the Node-Bs 140 a, 140 b may be in communicationwith the RNC 142 a. Additionally, the Node-B 140 c may be incommunication with the RNC 142 b. The Node-Bs 140 a, 140 b, 140 c maycommunicate with the respective RNCs 142 a, 142 b via an Iub interface.The RNCs 142 a, 142 b may be in communication with one another via anIur interface. Each of the RNCs 142 a, 142 b may be configured tocontrol the respective Node-Bs 140 a, 140 b, 140 c to which it isconnected. In addition, each of the RNCs 142 a, 142 b may be configuredto carry out or support other functionality, such as outer loop powercontrol, load control, admission control, packet scheduling, handovercontrol, macrodiversity, security functions, data encryption, and thelike.

FIG. 1C is a system diagram of the RAN 104 and the core network 106according to another embodiment. As noted above, the RAN 104 may employan E-UTRA radio technology to communicate with the WTRUs 102 a, 102 b,102 c over the air interface 116. The RAN 104 may also be incommunication with the core network 106.

The RAN 104 may include eNode Bs 160 a, 160 b, 160 c, though it will beappreciated that the RAN 104 may include any number of eNode Bs whileremaining consistent with an embodiment. The eNode Bs 160 a, 160 b, 160c may each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In one embodiment,the eNode Bs 160 a, 160 b, 160 c may implement MIMO technology. Thus,the eNode B 160 a, for example, may use multiple antennas to transmitwireless signals to, and receive wireless signals from, the WTRU 102 a.

Each of the eNode Bs 160 a, 160 b, 160 c may be associated with aparticular cell (not shown) and may be configured to handle radioresource management decisions, handover decisions, scheduling of usersin the uplink and/or downlink, and the like. As shown in FIG. 1C, theeNode Bs 160 a, 160 b, 160 c may communicate with one another over an X2interface.

The core network 106 shown in FIG. 1C may include a mobility managementgateway (MME) 162, a serving gateway (SGW) 164, and a packet datanetwork (PDN) gateway (PGW) 166. While each of the foregoing elementsare depicted as part of the core network 106, it will be appreciatedthat any one of these elements may be owned and/or operated by an entityother than the core network operator.

The MME 162 may be connected to each of the eNode Bs 160 a, 160 b, 160 cin the RAN 104 via an S1 interface and may serve as a control node. Forexample, the MME 162 may be responsible for authenticating users of theWTRUs 102 a, 102 b, 102 c, bearer activation/deactivation, selecting aparticular SGW during an initial attach of the WTRUs 102 a, 102 b, 102c, and the like. The MME 162 may also provide a control plane functionfor switching between the RAN 104 and other RANs (not shown) that employother radio technologies, such as GSM or WCDMA.

The SGW 164 may be connected to each of the eNode Bs 160 a, 160 b, 160 cin the RAN 104 via the S1 interface. The SGW 164 may generally route andforward user data packets to/from the WTRUs 102 a, 102 b, 102 c. The SGW164 may also perform other functions, such as anchoring user planesduring inter-eNode B handovers, triggering paging when downlink data isavailable for the WTRUs 102 a, 102 b, 102 c, managing and storingcontexts of the WTRUs 102 a, 102 b, 102 c, and the like.

The SGW 164 may also be connected to the PGW 166, which may provide theWTRUs 102 a, 102 b, 102 c with access to packet-switched networks, suchas the Internet 110, to facilitate communications between the WTRUs 102a, 102 b, 102 c and IP-enabled devices.

The core network 106 may facilitate communications with other networks.For example, the core network 106 may provide the WTRUs 102 a, 102 b,102 c with access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, 102 c andtraditional land-line communications devices. For example, the corenetwork 106 may include, or may communicate with, an IP gateway (e.g.,an IP multimedia subsystem (IMS) server) that serves as an interfacebetween the core network 106 and the PSTN 108. In addition, the corenetwork 106 may provide the WTRUs 102 a, 102 b, 102 c with access to thenetworks 112, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

FIG. 2 is a block diagram illustrating an example proximity service(ProSe) architecture 200 implemented in public land mobile networks(PLMNs) 230, 232 and 234. The ProSe architecture 200 may include WTRUs202 a and 202 b configured with respective ProSe applications 203 a and203 b; ProSe application servers 272 a and 272 b; ProSe functions 270 a,270 b and 270 c; home subscriber server (HSS) 212; MMES 262 b and 262 c(which may be connected to or co-located with a respectiveServing/Packet Data Network (PDN) Gateway (S/PGW)); and/or evolved UMTSTerrestrial Radio Access Networks (E-UTRANs) 204 a and 204 c. Each ofthe E-UTRANs 204 a and 204 c may include one or more eNode Bs (eNBs, notshown).

The ProSe architecture 200 may support various reference points, suchas, for example, described in the following. PC1 may be the referencepoint between the ProSe application 203 a or 203 b (in WTRU 202 a or 202b, respectively), and respective ProSe application servers 272 a or 272b. The PC1 may be used to define application level signalingrequirements. PC2 may be the reference point between the ProSeapplication server 272 a or 272 b and a respective ProSe function 270 aor 270 b. PC2 may be used to define the interaction between ProSeapplication server 272 a or 272 b and ProSe functionality (e.g. nametranslation) provided by the Third Generation Partnership Project (3GPP)evolved packet system (EPS) (not shown) via the respective ProSefunction 270 a or 270 b for EPC-level ProSe discovery.

PC3 may be the reference point between the WTRU 202 a and/or 202 b andthe ProSe functions 270 a, 270 b and/or 270 c. PC3 may use the evolvedpacket core (EPC) user plane for transport (e.g., an “over IP” referencepoint). PC3 may be used to authorize ProSe direct discovery andEPC-level ProSe Discovery requests and may perform allocation of ProSeapplication codes corresponding to ProSe application identities used forProSe direct discovery. PC3 may be used to define the authorizationpolicy per PLMN for ProSe direct discovery (e.g. for Public Safety andnon-Public Safety) and communication (e.g. for Public Safety) betweenWTRUs 202 a and/or 202 b and the ProSe functions 270 a, 270 b, and/or270 c.

PC4a may be the reference point between the HSS 212 and ProSe function270 b. The PC4a may be used to provide subscription information in orderto authorize access for ProSe direct discovery and ProSe directcommunication on a per PLMN basis. It may be used by the ProSe function270 a (e.g., EPC-level ProSe Discovery function) for retrieval ofEPC-level ProSe Discovery related subscriber data. PC5 may be thereference point between WTRUs 202 a and 202 b and may be used for thecontrol plane and/or user plane for ProSe direct discovery, ProSe directcommunication, and/or ProSe WTRU-to-Network Relay. When the WTRU 202 bis not roaming (as shown), PC6 may be the reference point between theProSe function 270 b in the home PLMN (HPLMN) 234 for the WTRU 202 b andthe ProSe function 270 a in the PLMN 230. PC6 may be used, for example,to authorize ProSe direct discovery requests, and/or perform allocationof ProSe application identity codes and ProSe application identity namesfrom the HPLMN 232 of the WTRU 202 b. PC6 may be used for HPLMN controlof ProSe service authorization.

When the WTRU 202 a is roaming (as shown), PC7 may be the referencepoint between the ProSe function 270 a in the HPLMN 230 of WTRU 202 aand the ProSe function 270 c in the visited PLMN (VPLMN) 230 (oralternatively, the ProSe function 270 b in the PLMN 234). PC7 may beused to authorize ProSe direct discovery requests, and/or may performallocation of ProSe application identity codes and ProSe applicationidentity names from the HPLMN 234 for WTRU 202 b. PC7 may be used forHPLMN control of ProSe service authorization.

S6a may be the reference point used to download ProSe relatedsubscription information to MME 262 during an E-UTRAN 204 attachprocedure or to inform the MME 262 that MME subscription information inthe HSS 212 has changed. S1 (S1-MME) may be used in ProSe to provide anindication from the MME 262 c or 262 b to an eNB in the E-UTRAN 204 c or204 b, respectively, that the respective WTRU 202 a or 202 b may beauthorized to use ProSe direct discovery. The LTE-Uu interface may beused between the WTRUs 202 a and 202 b and the E-UTRAN 204 a and 204 c,respectively. The LTE-Uu interface may be used to communicate controlmessages between the WTRUs 202 a and 202 b and the LTE system and/or fortransporting user plane data between the WTRUs 201 and 202 and theInternet.

The ProSe function 270 may be a network element (e.g., a logicalfunction implemented in a network element) used for network relatedactions required for ProSe. The ProSe function 270 may assume differentroles for different features of ProSe (each a “ProSe feature”). TheProSe function 270 may include various sub-functions that performdifferent roles depending on the ProSe feature. These sub-functions mayinclude a direct provisioning function (DPF), a direct discovery namemanagement function (DDNMF) and an EPC-level discovery ProSe function.

The DPF may be used to provision a WTRU 202 with parameters in order touse ProSe direct discovery and/or Prose direct communication. The DPFmay be used to provision WTRUs with PLMN-specific parameters that allowa WTRU 202 to use ProSe in the specific PLMN. In an example, for directcommunication used for Public Safety, the DPF may provision the WTRU 202with parameters that may be used when the WTRU 202 is served by E-UTRAN.

The DDNMF may be used for open ProSe direct discovery to allocate and/orprocess the mapping of ProSe applications identities (IDs) and/or ProSeapplication codes used in ProSe direct discovery. The DDNMF may useProSe related subscriber data stored in an HSS 212 for authorization ofeach discovery request. The DDNMF may also provide the WTRU 202 withsecurity material so that the WTRU may protect discovery messagestransmitted over the air.

The EPC-level Discovery ProSe function may have a reference pointtowards the application server 272 (e.g., reference point PC2), towardsthe HSS 212 (e.g., reference point PC4a) and towards the WTRU 202 (e.g.,reference point PC3). The functionality of the EPC-level Discovery ProSefunction may include any of the following: storage of ProSe relatedsubscriber data and/or retrieval of ProSe-related subscriber data fromthe HSS 212; authorization and/or configuration of the WTRU forEPC-level ProSe Discovery and/or EPC-assisted WLAN direct discovery andcommunication; storage of a list of applications that may be authorizedto use EPC-level ProSe Discovery and EPC-assisted WLAN direct discoveryand communication; acting as a location services client (e.g. ServiceLocation Protocol (SLP) agent) to enable EPC-level ProSe Discovery;providing the WTRU 202 with information to assist WLAN direct discoveryand communications; handling of EPC ProSe Subscriber IDs and applicationLayer User IDs; security related functionality; interaction with WTRU202 over PC3 reference point; interaction with third party applicationservers over a PC2 reference point; interaction with ProSe functions 270in other PLMNs over a PC6 reference point; support for functionality forrequesting WTRU location via the HSS 212; and/or providing functionalityfor charging via the EPC or outside of the EPC (e.g. offline charging).The ProSe function 270 may provide charging functionality for usage ofProSe, which may include ProSe via the EPC and/or for ProSe directdiscovery and ProSe direct communication.

Example ProSe Direct Discovery Procedures

ProSe direct discovery as used herein may refer to one of various directdiscovery procedures. Any of these direct discovery procedures may bebased on a discovery model. Examples of the discovery model may includea Model A (“I am here”) and a Model B (“who is there?”/“Are youthere?”).

Model A defines two roles for ProSe-enabled WTRUs (WTRUs configured withProSe applications) that participate in ProSe direct discovery. Thefirst role is as an announcing WTRU, and the second role is as amonitoring WTRU. Under the first role, the announcing WTRU may announcecertain information that may be used by WTRUs in proximity that havepermission to discover. Under the second role, the monitoring WTRU maymonitor for certain information of interest while within proximity ofannouncing WTRUs.

The announcing WTRU may broadcast discovery messages at pre-defineddiscovery intervals, and the monitoring WTRUs that may be interested inthese messages may read them and may process them. Model A may beconsidered as equivalent to “I am here” because the announcing WTRU maybroadcast information about itself, e.g., its ProSe applicationidentities or ProSe WTRU identities, in the discovery message.

Model B defines two roles for ProSe-enabled WTRUs that participate inProSe direct discovery. The first role is as a Discoverer WTRU, and thesecond role is as a Discoveree WTRU. A ProSe-enabled WTRU participatingunder the first role as a Discoverer WTRU may request information aboutwhat it is interested to discover. A ProSe-enabled WTRU participatingunder the second role as a Discoveree WTRU may receive the request, andmay respond with some information related to the Discoverer WTRUrequest.

Under Model B discovery, both Discoverer WTRU and Discoveree WTRUperform monitoring and announcing operations. The Discoverer WTRUperforms an announcing operation followed by a monitoring operation, andthe Discoveree WTRU performs a monitoring operation followed by anannouncing operation. The Discoverer WTRU, for example, may announce aProSe query code, and then may monitor for a ProSe response code. TheDiscoveree WTRU, conversely, may monitor for a ProSe query code, andthen may announce a ProSe response code.

Under Model B discovery, the ProSe query code may be allocated by aProSe function in an HPLMN of the Discoveree (“Discoveree (H)ProSefunction”), and may then be passed to a ProSe function in an HPLMN ofthe Discoverer (“Discoverer (H)ProSe function”) as part of a DiscovererWTRU request procedure. The ProSe query code may be broadcasted by theDiscoverer WTRU over the air (e.g., via the PC5 interface).

The ProSe response code may be allocated and/or provided to theDiscoveree WTRU by the Discoveree (H)ProSe function as part of aDiscoveree WTRU request procedure. The ProSe response code may be sentby the Discoveree WTRU over the air (PC5 interface) after receiving aProSe query code that matches a discovery filter employed by theDiscoveree WTRU.

After receiving the ProSe response code from the Discoveree WTRU, amatch report procedure may be initiated by the Discoverer WTRU toacquire a ProSe application ID from the Discoverer (H)ProSe function.

As one of ordinary skill in the art would recognize, both DiscovererWTRUs and monitoring WTRUs are configured to look for a service, and onemay be substituted for the other in the embodiments herein withoutmodification or with modification well within ordinary skill in the artbased on (at least on) the teachings herein. Similarly, both DiscovereeWTRUs and announcing WTRUs are configured to provide a service, and onemay be substituted for the other in the embodiments herein withoutmodification or with modification well within ordinary skill in the artbased on (at least on) the teachings herein.

This disclosure is drawn, inter alia, to methods, apparatus, systems,devices, and computer program products directed to enhancements toproximity-based services (ProSe) direct discovery. Among the methods isa method that be implemented in a ProSe function and that may includereceiving a discovery request message including a ProSe applicationidentifier; determining whether or not the ProSe function can retrieve avalid ProSe application code corresponding to the ProSe applicationidentifier; and transmitting a reject-type discovery response messageconditioned on the determining that a valid ProSe application code isnot available to the ProSe function.

Among the apparatus is a ProSe function that may include circuitry,including a processor and instructions executable by the processor, andthat may be configured to receive a discovery request message includinga ProSe application identifier; determine whether or not the ProSefunction can retrieve a valid ProSe application code corresponding tothe ProSe application identifier; and transmit a reject-type discoveryresponse message conditioned on the determining that a valid ProSeapplication code is not available to the ProSe function.

Among the methods is a method that may be implemented in a WTRUparticipating in a ProSe direct discovery procedure, and that mayinclude sending a match report request message to a ProSe function afterexpiry of a match report refresh timer and prior to expiry of a validitytimer of a ProSe code; receiving a match report reject message from theProSe function; and stopping the validity timer responsive to the matchreport reject message.

Among the methods is a method that may be implemented in a WTRUparticipating in a ProSe direct discovery procedure, and that mayinclude sending multiple match report request messages to a ProSefunction after expiry of a match report refresh timer and prior toexpiry of a validity timer of a ProSe code; and stopping the validitytimer on condition that the WTRU does not receive a match reportacknowledgement for any of the multiple match report request messages.

In an embodiment the method may further include informing upper layersof the WTRU that the ProSe code is no longer valid. In an embodiment,the method may include sending a new match report request message afterstopping the validity timer. In an embodiment, the new match reportrequest message may be sent at a next match event. In an embodiment, thematch report reject message may include a cause value indicating aninvalid MIC. In an embodiment, the match report reject message is amatch report acknowledgement message.

Among the apparatus is a WTRU configured to participate in a ProSedirect discovery procedure. The WTRU may include a transmitter, areceiver, a processor, a match report refresh timer and a validity timerof a ProSe code. The processor in combination with the transmitter maybe configured to send a match report request message to a ProSe functionafter expiry of the match report refresh timer and prior to expiry ofthe validity timer of a ProSe code; the receiver may be configuredreceive a match report reject message from the ProSe function; and theprocessor may be configured to stop the validity timer responsive to thematch report reject message.

In an embodiment, the processor in combination with the transmitter maybe configured to send multiple match report request messages to a ProSefunction after expiry of a match report refresh timer and prior toexpiry of a validity timer of a ProSe code; and the processor may beconfigured to stop the validity timer on condition that a match reportacknowledgement for any of the multiple match report request messages isnot received by the WTRU.

In an embodiment, the processor may be configured to inform upper layersof the WTRU that the ProSe code is no longer valid. In an embodiment,the processor in combination with the transmitter may be configured tosend a new match report request message after stopping the validitytimer. In an embodiment, the new match report request message may besent at a next match event. In an embodiment, the match report rejectmessage may include a cause value indicating an invalid MIC. In anembodiment, the match report reject message may be a match reportacknowledgement message.

Among the methods is a method that may be implemented in a WTRU and thatmay include sending a first match report request message to a ProSefunction after expiry of a match report refresh timer and prior toexpiry of a validity timer of a ProSe code; receiving a first matchreport reject message from the ProSe function; sending a second matchreport request message to the ProSe function after expiry of the matchreport refresh timer and prior to expiry of the validity timer; andreceiving a match report acknowledgement for the second match reportrequest message.

In an embodiment, the method may further include informing upper layersof the WTRU that the ProSe code is no longer valid. In an embodiment,the match report reject message nay include a cause value indicating aninvalid MIC. In an embodiment, the match report reject message is amatch report acknowledgement message.

Among the apparatus is a WTRU that may include a transmitter, areceiver, a processor, a match report refresh timer and a validity timerof a ProSe code. The processor in combination with the transmitter maybe configured to send a first match report request message to a ProSefunction after expiry of the match report refresh timer and prior toexpiry of the validity timer; the receiver may be configured to receivea first match report reject message from the ProSe function; theprocessor in combination with the transmitter may be configured to senda second match report request message to the ProSe function after expiryof the match report refresh timer and prior to expiry of the validitytimer; and the receiver may be configured to receive a match reportacknowledgement for the second match report request message.

In an embodiment, the processor may be configured to inform upper layersof the WTRU that the ProSe code is no longer valid. In an embodiment,the first match report reject message comprises a cause value indicatingan invalid MIC. In an embodiment, any of the first and second matchreport reject messages is a match report acknowledgement message. In anembodiment,

Among the methods is a method that may be implemented in a ProSefunction and that may include receiving multiple match report requestmessages from a WTRU after expiry of a match report refresh timer andprior to expiry of a validity timer of a ProSe code; and sending, to theWTRU, a match report reject message for each of the multiple matchreport request messages.

In an embodiment, the method may further include receiving a new matchreport request message at a next match event. In an embodiment, thematch report reject message may include a cause value indicating aninvalid MIC. In an embodiment, the match report reject message may be amatch report acknowledgement message.

Among the apparatus is a ProSe function that may include circuitry,including a processor and instructions executable by the processor, andthat may be configured to receive multiple match report request messagesfrom a WTRU after expiry of a match report refresh timer and prior toexpiry of a validity timer of a ProSe code; and send, to the WTRU, amatch report reject message for each of the multiple match reportrequest messages.

In an embodiment, the circuitry may be configured to receive a new matchreport request message at a next match event. In an embodiment, thematch report reject message may include a cause value indicating aninvalid MIC. In an embodiment, the match report reject message is amatch report acknowledgement message.

Among the methods is a method that may be implemented in a ProSefunction and that may include receiving a first match report requestmessage from a wireless transmit/receive WTRU after expiry of a matchreport refresh timer and prior to expiry of a validity timer of a ProSecode; sending a first match report reject message to the WTRU; receivinga second match report request message from the WTRU after expiry of thematch report refresh timer and prior to expiry of the validity timer;and sending a match report acknowledgement for the second match reportrequest message.

In an embodiment, the first match report reject message may include acause value indicating an invalid MIC. In an embodiment, any of thefirst and second match report reject messages may be a match reportacknowledgement message.

Among the apparatus is a ProSe function that may include circuitry,including a processor and instructions executable by the processor, andthat may be configured to receive a first match report request messagefrom a wireless transmit/receive WTRU after expiry of a match reportrefresh timer and prior to expiry of a validity timer of a ProSe code;send a first match report reject message to the WTRU; receive a secondmatch report request message from the WTRU after expiry of the matchreport refresh timer and prior to expiry of the validity timer; and senda match report acknowledgement for the second match report requestmessage.

In an embodiment, the first match report reject message may include acause value indicating an invalid MIC. In an embodiment, any of thefirst and second match report reject messages is a match reportacknowledgement message.

Among the methods is a method implemented in a Discoverer WTRUparticipating in a ProSe direct discovery procedure. The method mayinclude transmitting a first discovery message including a metadata flagthat signals a desire to obtain metadata from a Discoveree WTRUparticipating in the ProSe direct discovery procedure. The method mayinclude receiving, from the Discoveree WTRU, a second discovery messageincluding the metadata.

Also among the methods is a method implemented in a Discoveree WTRUparticipating in a ProSe direct discovery procedure. The method mayinclude receiving, from a Discoverer WTRU participating in the ProSedirect discovery procedure, a first discovery message including ametadata flag that signals a desire to obtain metadata from theDiscoveree WTRU. The method may also include transmitting, to theDiscoverer WTRU, a second discovery message including the metadata.

In an embodiment, the first discovery message may include a ProSe querycode. In an embodiment, the second discovery message may include a ProSeresponse code. In an embodiment, any of the first and second discoverymessages may be communicated using respective PC5 reference points ofthe Discoverer WTRU and the Discoveree WTRU. In an embodiment, themetadata is transmitted between the first and second WTRUs via an airinterface.

Another of the methods may be a method implemented in a ProSe functionassociated with a Discoveree WTRU participating in a ProSe directdiscovery procedure. The method may include receiving, from theDiscoveree WTRU, a first discovery message including metadata associatedwith Discoveree WTRU; and transmitting, to a ProSe function associatedwith a Discoverer WTRU participating in the ProSe direct discoveryprocedure, a second discovery message including the metadata associatedwith the Discoveree WTRU.

In an embodiment, the method may include storing the metadata associatedwith the Discoveree WTRU. In an embodiment, the method may includeextracting the metadata from storage. In an embodiment, the firstdiscovery message may include a command field set to ProSe response. Inan embodiment, the second discovery message may include any of a ProSequery code and a ProSe response code.

Another of the methods may be a method implemented in a ProSe functionassociated with a Discoverer WTRU participating in a ProSe directdiscovery procedure. The method may include receiving, from a ProSefunction associated with a Discoveree WTRU participating in the ProSedirect discovery procedure, a discovery message including metadataassociated with the Discoveree WTRU; receiving, from the DiscovererWTRU, a match report message including a metadata flag signaling adesire to obtain metadata associated with a Discoveree WTRU; andtransmitting, to the Discoverer WTRU, a match report acknowledgementmessage including the metadata associated with the Discoveree WTRU.

In an embodiment, the method may include storing the metadata associatedwith the Discoveree WTRU. In an embodiment, the method may includeextracting the metadata from storage. In an embodiment, the firstdiscovery message may include a command field set to ProSe response. Inan embodiment, the second discovery message may include any of a ProSequery code and a ProSe response code.

Another of the methods may be a method implemented in a ProSe functionassociated with a Discoveree WTRU participating in a ProSe directdiscovery procedure. The method may include receiving, from theDiscoveree WTRU, a first discovery message including a metadata flagsignaling a desire to obtain metadata associated with a Discoverer WTRUparticipating in the ProSe direct discovery procedure; and transmitting,to a ProSe function associated with the Discoverer WTRU, a seconddiscovery message including the metadata flag.

In an embodiment, the first discovery message may include a commandfield set to ProSe response. In an embodiment, the second discoverymessage may include any of a ProSe query code and a ProSe response code.In an embodiment, the method may further include receiving, from theProSe function associated with the Discoverer WTRU, a match reportmessage including metadata associated with the Discoverer WTRU. In anembodiment, the method may further include transmitting, to theDiscoveree WTRU, a match report message including the metadataassociated with the Discoverer WTRU.

Another of the methods may be a method implemented in a ProSe functionassociated with a Discoverer WTRU wireless participating in a ProSedirect discovery procedure. The method may include receiving, from aProSe function associated with a Discoveree WTRU participating in theProSe direct discovery procedure, a first discovery message including ametadata flag signaling a desire to obtain metadata associated with aDiscoverer WTRU; and transmitting, to the Discoverer WTRU, a seconddiscovery message including the metadata flag.

In an embodiment, any of the first and second discovery messages mayinclude a ProSe query code. In an embodiment, any of the first andsecond discovery messages may be communicated using respective PC5reference points of the Discoverer WTRU and the Discoveree WTRU. In anembodiment, the metadata may be transmitted between the first and secondWTRUs via an air interface.

Another of the methods may be a method implemented a Discoverer WTRUparticipating in a ProSe direct discovery procedure. The method mayinclude receiving, from a ProSe function associated with the DiscovererWTRU, a first discovery message including a metadata flag signaling adesire to obtain metadata associated with the Discoverer WTRU; andtransmitting, to a Discoveree WTRU participating in the ProSe directdiscovery procedure, a second discovery message including the metadataassociated with the Discoverer WTRU.

In an embodiment, the first discovery message may include a commandfield set to ProSe response. In an embodiment, the second discoverymessage may include a ProSe query code. In an embodiment, the seconddiscovery message may be communicated using respective PC5 referencepoints of the Discoverer WTRU and the Discoveree WTRU. In an embodiment,the metadata is transmitted between the first and second WTRUs via anair interface.

Another of the methods may be a method implemented in a Discoveree WTRUparticipating in a ProSe direct discovery procedure. The method mayinclude transmitting, to a ProSe function associated with the DiscovereeWTRU, a first discovery message including a metadata flag signaling adesire to obtain metadata associated with the Discoverer WTRU; andreceiving, from a Discoverer WTRU participating in the ProSe directdiscovery procedure, a second discovery message including the metadataassociated with the Discoverer WTRU.

In an embodiment, the discovery message may include a ProSe responsecode. In an embodiment, the discovery message may be communicated usingrespective PC5 reference points of the Discoverer WTRU and theDiscoveree WTRU.

Another of the methods may be a method implemented in a Discoveree WTRUparticipating in a ProSe direct discovery procedure. The method mayinclude transmitting, to a Discoverer WTRU participating in the ProSedirect discovery procedure, a discovery message including a metadataflag signaling a desire to obtain metadata associated with theDiscoverer WTRU; receiving, from a ProSe function associated with theDiscoveree WTRU, a match report message including the metadataassociated with the Discoverer WTRU.

Another of the methods may be a method implemented in a ProSe functionassociated with a Discoveree WTRU participating in a ProSe directdiscovery procedure. The method may include receiving, from a ProSefunction associated with a Discoverer WTRU participating in the ProSedirect discovery procedure, a first match report message includingmetadata associated with the Discoverer WTRU; transmitting, to theDiscoveree WTRU, a second match report message including the metadataassociated with the Discoverer WTRU.

Another of the methods may be a method implemented in a ProSe functionassociated with a Discoverer WTRU participating in a ProSe directdiscovery procedure. The method may include receiving, from theDiscoverer WTRU, a first match report message including metadataassociated with the Discoverer WTRU; and transmitting, to a ProSefunction associated with a Discoveree WTRU participating in a ProSedirect discovery procedure, a second match report message including themetadata associated with the Discoverer WTRU.

Another of the methods may be a method implemented in a ProSe functionassociated with a Discoveree WTRU participating in a ProSe directdiscovery procedure. The method may include receiving, from theDiscoveree WTRU, a first discovery message including informationcorresponding to a ProSe code suffix; transmitting, to a ProSeapplication server, a first authentication message including theinformation corresponding to a ProSe code suffix; receiving, from theProSe application server, a second authentication message including aProSe code suffix pool and one or more ProSe code suffix masks; andtransmitting, to the Discoveree WTRU, a second discovery messageincluding the ProSe code suffix pool.

Another of the methods may be a method implemented in a Discoveree WTRUparticipating in a ProSe direct discovery procedure. The method mayinclude transmitting, to a ProSe function associated with the DiscovereeWTRU, a first discovery message including information corresponding to aProSe code suffix; and receiving, from the ProSe function associatedwith the Discoveree WTRU, a ProSe application server, a second discoverymessage including the ProSe code suffix pool.

Another of the methods may be a method implemented in a ProSe functionassociated with a Discoverer WTRU participating in a ProSe directdiscovery procedure. The method may include receiving, from theDiscoveree WTRU, a first discovery message including informationcorresponding to a ProSe code suffix; transmitting, to a ProSeapplication server, a first authentication message including theinformation corresponding to a ProSe code suffix; receiving, from theProSe application server, a second authentication message including aProSe code suffix pool and one or more ProSe code suffix masks;transmitting, to a ProSe function associated with a Discoveree WTRUparticipating in the ProSe direct discovery procedure, a discoveryrequest message; receiving, from the ProSe associated with a DiscovereeWTRU, a discovery response message including a ProSe code suffix pool;and transmitting, to the Discoverer WTRU, a second discovery messageincluding the ProSe code suffix pool.

Another of the methods may be a method implemented in a Discoverer WTRUparticipating in a ProSe direct discovery procedure. The method mayinclude transmitting, to a ProSe function associated with the DiscovererWTRU, a first discovery message including information corresponding to aProSe code suffix; receiving, from the ProSe function associated withthe Discoveree WTRU, a second discovery message including the ProSe codesuffix pool.

In an embodiment of the preceding methods and/or apparatuses, the ProSedirect discovery procedure may be any of a Model A direct discoveryprocedure and a ProSe Model B direct discovery procedure.

Referring now to FIG. 3, a flow diagram illustrating an example ProSeModel B direct discovery procedure 300 is shown. The ProSe Model Bdirect discovery procedure 300 may be carried out by a Discoveree WTRU302 a, a Discoveree ProSe function 370 a, a Discoverer WTRU 302 b and aDiscoverer ProSe function 370 b. The ProSe Model B direct discoveryprocedure 300 may be carried out in three phases, namely, a DiscovereeWTRU request procedure, a Discoverer WTRU request procedure and adirect-communication discovery procedure between Discoveree WTRU 302 aand the Discoverer WTRU 302 b.

The Discoveree WTRU request procedure may be carried out as follows. TheDiscoveree WTRU 302 a may send a discovery request message 301 to theDiscoveree ProSe function 370 a. After receiving the discovery requestmessage 301, the Discoveree ProSe function 370 a may allocate a ProSeresponse code, the ProSe query code and one or more discovery filters(corresponding to the ProSe query code). The Discoveree ProSe function370 a may send a discovery response message 303 to the Discoveree WTRU302 a. The discovery response message 303 may include the allocatedProSe response code and discovery filters. After receiving the discoveryresponse message 303, the Discoveree WTRU 302 a may extract theallocated ProSe response code and discovery filters and may beginmonitoring for ProSe query codes matching the allocated discoveryfilters.

The Discoverer WTRU request procedure may be carried out as follows. TheDiscoverer WTRU 302 b may send a discovery request message 305 to theDiscoverer ProSe function 370 b. Thereafter, the Discoverer ProSefunction 370 b may interact with the Discoveree ProSe function 370 a toobtain therefrom the allocated ProSe query and response codes (as bothof codes were allocated by the Discoveree ProSe function 370 a as partof the Discoveree WTRU request procedure). To facilitate the exchange,the Discoverer ProSe function 370 b may send a discovery request message307 to the Discoveree ProSe function 370 a. The Discoveree ProSefunction 370 a may send a discovery response message 309 to theDiscoverer ProSe function 370 b. The discovery response message 309 mayinclude the ProSe query and response codes.

After receiving the ProSe query and response codes, the Discoverer ProSefunction 370 b may generate one or more discovery filters based on thereceived ProSe response code. For each ProSe query code, the DiscovererProSe function 370 b may generate one or more discovery filters based onthe received ProSe response code so that the Discoverer WTRU 302 b canmonitor and determine the ProSe response code that matches the discoveryfilter(s). The Discoverer ProSe function 370 b may send a discoveryresponse message 311 to the Discoverer WTRU 302 b. The discoveryresponse message 311 may include the ProSe query code and the discoveryfilters. The Discoverer WTRU 302 b may receive the discovery responsemessage 311, extract the allocated ProSe query code and discoveryfilters.

The direct-communication discovery procedure be carried out as follows.The Discoverer WTRU 302 b may broadcast (announce) the ProSe query code,and may begin monitoring for ProSe response codes corresponding to thebroadcast ProSe query code. The Discoveree WTRU 302 a may respond to thebroadcasted ProSe query code by sending (announcing) to the DiscovererWTRU 302 b the ProSe response code it received from the Discoveree ProSefunction 370 b. Thereafter, the Discoverer WTRU 302 b may carry out aProSe match report procedure.

In the description of the ProSe Model B direct discovery procedure 300above, the Discoveree WTRU request procedure is carried out first, theDiscoverer WTRU request procedure is carried out next, followed by thedirect-communication discovery procedure. Pursuant to the methodologiesand technologies provided herein, the Discoverer WTRU may make adiscovery request before the Discoveree WTRU makes a discovery requestnotwithstanding the possibility that, when the discovery request isreceived from the Discoverer WTRU, a valid ProSe code of a target ProSeapplication user might not be available in the ProSe functions becausethe target application user (Discoveree WTRU) has yet to initiate adiscovery request. This may be particularly beneficial in view of usingProSe Model B direct discovery procedure for the public safetyusers/groups.

FIG. 4 is a flow diagram illustrating an example procedure 400. Forsimplicity of exposition, the procedure 400 is described with respect tothe Model B direct discovery procedure 300 of FIG. 3. The DiscovererProSe function 370 b may receive a discovery request message from theDiscoverer WTRU 302 b (402). Responsive to the discovery requestmessage, the Discoverer ProSe function 370 b may request a ProSe querycode from the Discoveree ProSe function 370 a (404). The DiscovereeProSe function 370 a may determine whether the ProSe query code isretrievable or otherwise available (406). If the ProSe query code isretrievable or otherwise available, then the Discoveree ProSe function370 a may send an accept-type discovery response message to theDiscoverer ProSe function 370 a (408). If the ProSe query code is notretrievable or otherwise available, then the Discoveree ProSe function370 a may send a reject-type discovery response message to theDiscoverer ProSe function 370 a (410). The reject-type discovery messagemay include an appropriate cause indication/value (e.g., an indicationof “No valid Discovery Filters” and/or “No valid ProSe code available”).Although not shown, the Discoverer ProSe function 370 a may send areject-type discovery response message to the Discoverer 302 b. Thisreject-type discovery message may include an appropriate causeindication/value, (e.g., an indication of “No valid Discovery Filters”and/or “No valid ProSe code available), as well.

In an embodiment, when a ProSe function receives a discovery requestfrom a Discoverer WTRU and fails to retrieve a ProSe code of a targetProSe application user, the ProSe function may initiate a announcerequest to a ProSe application server indicating that a discoveryrequest towards the user has been issued and that an announcingprocedure may be initiated by the target user.

To facilitate the announce request, a discovery trigger message from theProSe function to the ProSe application server over PC2 interface may beused. The discovery trigger message may include a Target RestrictedProse App User ID, a Discoverer UE's Restricted Prose App User ID, andRequest Type (=e.g., “Model B Discovery”).

Upon receiving the discovery trigger message from the ProSe function,the ProSe application server may use application layer signaling (e.g.,over a PC1 interface) to inform the target user that there's discoveryinterest towards it and announcing may be required. The ProSeapplication server may also translate the Discoverer restricted ProseApp User ID into an application User ID and may send it to the targetuser. The target user may use such other another application User ID todetermine who is interested in discovering the target user and, in turn,as a factor in deciding whether to accept the request or not.

If the target user accepts the request, the target user may initiate adiscovery request procedure. The target user may also confirm with theProSe application server that it has started the discovery requestprocedure. The ProSe application server may send a response message tothe Discoverer ProSe function to inform that the target user has startedannouncing. The ProSe application server may send the ProSe query codeand ProSe response code to the Discoverer ProSe function.

Alternatively, after receiving the confirmation from the ProSeapplication server, the ProSe function may return a Discovery responseto the Discoverer that the target user is not available at present butit should retry later. In some embodiment, a timer may be included inthe message to indicate a period of time to wait before a retry.

In another embodiment, when the ProSe application server receives thediscovery trigger and the ProSe application server maintains a bindingbetween a Target Restricted ProSe application ID and a target restrictedProSe discovery WTRU ID, which may be available because the announcingprocedure of the target user was carried out before, the ProSeapplication server may be able to identify the target user ProSefunction so it may trigger the announcing procedure by forwarding therequest message to the ProSe function and then the target user ProSefunction may use PC3 signaling to inform the target user to start theannouncing procedure.

In an embodiment, a Discoveree ProSe function, after receiving discoveryrequest message from a Discoverer, may trigger a discovery request overPC3 directly without going through a ProSe application server. The PC3message may include one or more of the parameters described above inconnection with the discovery trigger to the ProSe application server.The Discoveree may then start a discovery request procedure. After thisprocedure is complete, the Discoveree ProSe function may reply back theDiscoverer ProSe function with a Discovery response message that mayinclude the ProSe query code and ProSe response code.

In an embodiment, if a Discoverer WTRU sends a discovery request beforea Discoveree WTRU, the request may be rejected by the Discoverer(H)ProSe function, when it does not receive any codes (ProSe query codeand ProSe response code) from Discoveree ProSe function. The DiscovererProSe function may send a discovery response without codes acknowledgingthe receipt of the discovery request message. The ProSe query code anddiscovery filters may be pushed on to the Discoverer WTRU when theDiscoverer WTRU registers. The registration may operate as a trigger tothe Discoveree ProSe function to send the codes to the Discoverer ProSefunction.

In an embodiment, when a Discoverer ProSe function sends a discoveryrequest to a Discoveree ProSe function, the Discoveree ProSe functionmay generate the codes and send them in a Discovery response message tothe Discoverer ProSe function. The ProSe query code and discovery filtermay be sent to the Discoverer WTRU with an indication to not announcethe code until the Discoveree WTRU sends a discovery request. After theDiscoveree WTRU sends the discovery request, the Discoveree ProSefunction may send a different indication to the Discoveree ProSefunction suggesting that the codes have been assigned to the DiscovereeWTRU. In turn, the Discoverer ProSe function may inform the DiscovererWTRU to start broadcasting/announcing ProSe query code.

In an embodiment, an inter-ProSe information exchange may be triggeredby a Discoveree WTRU after it transmits and receives confirmation of aDiscovery Request (Model=B, Discovery Type, Restricted ProSe App UserID, WTRU/UE ID, command=ProSe response, application ID) message. Thissituation may occur whenever the Discoveree WTRU changes its discoveryparameters before the validity timer expires. The Discoveree ProSefunction may be able to contact other ProSe functions which hadpreviously received ProSe query codes to exchange discovery informationand keep them up to date.

Interaction between a Discoverer ProSe function and Discoveree ProSefunction (refs. 511 and 513) of FIG. 5 may be part of a discoveryrequest procedure for a Discoveree WTRU. A ProSe query code and ProSeresponse code may be sent the Discoverer ProSe function as part of theDiscoveree WTRU discovery request procedure. In this way, the DiscovererProSe function may be kept up to date with the ProSe codes.

An alternative procedure to prevent outdated discovery filters and querycodes may be carried out by independently setting the durations ofvalidity timers at the Discoverer WTRU from the length of validitytimers at the Discoveree WTRU. The validity timer may be set up to beshorter for the discovery filters and ProSe query codes at theDiscoverer WTRU. Once the validity timer expires for the query code, atrigger may be configured at the WTRU so that it may send a newDiscovery Request (Model=B, Discovery Type, Restricted ProSe App UserID, WTRU/UE ID, command=ProSe query, application ID, applicationTransparent Container) message to receive the latest parameters. Theperiod of time during which it is using outdated discovery filters maybe reduced because the Discoverer ProSe function may perform regularupdates more frequently with the Discoveree ProSe function that assignedthe query code. The length of the validity timer for the Discovererparameters may be shorter than for the Discoveree parameters.

Due to mobility of the WTRUs, the Discoveree WTRU may change locationsafter having been configured for discovery. Pursuant to the newmethodologies and technologies herein, the Discoverer ProSe function maybe kept up to date with changes in the parameters (e.g. ProSe query codeand discovery filters) for discovery when the Discoveree PLMN changesand/or when the ProSe response code is not no longer being broadcasted(e.g., because Discoverer WTRU is not authorized by a VPLMN ProSefunction). Pursuant to the new methodologies and technologies herein,the discovery filter at the Discoverer WTRU for the ProSe response codemay be prevented from becoming obsolete when the Discoveree changesPLMNs.

Metadata Composition and Granularity Example

The metadata associated with a user may include a wide variety ofcomponents and information types. Examples of such information mayinclude one or more of a postal address, a phone number, a URL, alocation, service characteristics/attributes, and other applicationspecific data. In some embodiments, the Discoverer and/or Discoveree maybe interested to learn about only certain components of the metadata,instead of an entire comprehensive metadata container with most or allof its associated components and/or information types. Mechanismsprovided herein allow for fine metadata granularity in such instances,and as such, save network resources that would have otherwise beenwasted if the entire comprehensive metadata container is insteadprovided.

ProSe Code Application Suffix Example

In Model A restricted discovery, ProSe code may contain an applicationcontrolled extension, which is assigned by the application server. Thecomplete ProSe code broadcasted by the announcing WTRU may include (i) aprefix that is assigned by a ProSe function of an HPLMN of theannouncing WTRU, and (ii) a ProSe code suffix that is applicationcontrolled. The ProSe code suffix may represent application specificinformation (e.g., a group ID, etc.). Support for ProSe code prefix andProSe code suffix functionality in the Model B discovery procedure maybe beneficial. Mechanisms provided herein allow for appropriate andunambiguous ProSe code prefix and/or suffix assignment, use and othersupport.

Example Procedures for Metadata Transfers to Discoverer WTRUs

Given that Model B direct discovery is a two-way discovery where theDiscoverer WTRU and the Discoveree WTRU can directly exchange a ProSequery code and a ProSe response code, the Model B direct discoveryprocedure (and its back and forth interaction) offers another dimensionor plane for transporting the metadata between the Discoveree WTRU andDiscoverer WTRU upon demand.

In some embodiments, the Discoveree WTRU may be interested in obtainingmetadata associated with a Discoverer WTRU. As an example, a taxi driveroffering a taxi service may want to learn about a customer's desireddestination address so as to allow the taxi driver to filter only thosecustomers whose target destinations are of interest to the driver. Thetwo-way nature of Model B discovery, with both the Discoveree WTRU andDiscoverer WTRU performing monitoring and announcing operations, may beexploited to enable the Discoveree WTRU to obtain application-levelinformation (metadata) related to Discoverer WTRUs, and in turn,consider such information in connection with determining whichDiscoverer WTRUs to select and/or whether to select a particularDiscoverer WTRU.

Example Discoveree-to-Discoverer Direct Metadata Transfers

FIG. 6 is a message flow diagram illustrating an example metadatatransfer procedure 600 that may be carried out during adirect-communication discovery phase of a ProSe direct discoveryprocedure. A Discoveree WTRU 602 a may acquire a ProSe response code anddiscovery filters allocated by a ProSe function (not shown) responsiveto carrying out a Discoveree WTRU discovery request procedure (601). TheDiscoverer WTRU 602 b may acquire a ProSe query code and discoveryfilters allocated by the ProSe function responsive to carrying out aDiscoverer WTRU discovery request procedure (603).

After acquiring the allocated ProSe query code and discovery filters, adiscovery message 605 from the Discoverer WTRU 602 b may be broadcastedor otherwise wirelessly transmitted (e.g., broadcasted) over the air.The discovery message 605 may be transmitted on a PC5, for example. Thediscovery message 605 may include the acquired ProSe query code. Thediscovery message 605 may also include a flag or other indication(collectively “metadata flag”) that signals a desire to obtain metadatafrom a WTRU participating in direct discovery. The WTRU participating inthe direct discovery may be the (yet to be) discovered Discoveree WTRU602 a. While monitoring for discovery messages using its discoveryfilters (605), the Discoveree WTRU 602 a may detect the discoverymessage 605. Recognizing that the ProSe query code in the discoverymessage 605 is appropriate to respond to (609), and that such messageincludes the metadata flag, the Discoveree WTRU 602 a may forward themetadata together with the ProSe response code to the Discoverer WTRU602 b over the air in a discovery message 613 (e.g., on the PC5).

While monitoring for discovery messages using its discovery filters(611), the Discoverer WTRU 602 b may detect the discovery message 613.Recognizing that the ProSe response code in the discovery message 613matches its discovery filters (615), the Discoverer WTRU 602 b mayextract the metadata and use it as criteria in connection withperforming a match report procedure (617).

Because the WTRUs 602 a, 602 b can continue to announce theirquery/response codes prior to expiry of their corresponding validitytimers, the foregoing procedure may permit the Discoveree WTRU 602 a todynamically revise, update, replace, delete, remove, etc. the metadataat any time before expiration of its validity timer. Additionally, theDiscoverer WTRU 602 b may decide (at some point) that it does not desireto continue acquiring metadata. To effect this, the Discoverer WTRU 602b may exclude the metadata flag in a corresponding discovery message.Alternatively, the Discoverer WTRU 602 b may set the metadata flag to avalue indicating a desire not to acquire the metadata.

Example Inter-ProSe Function Metadata Transfer

FIGS. 7, 8 and 9 are message flow diagrams illustrating exampleprocedures for use in connection with inter-ProSe function metadatatransfer that may be carried out via Discoveree WTRU request procedure,Discoveree WTRU request procedure and direct-communication procedurephases of a ProSe direct discovery procedure. FIG. 7 illustrates anexample Discoveree WTRU request procedure. As part of the DiscovereeWTRU request procedure, a Discoveree WTRU may send to a Discoveree(H)ProSe function a discovery request message that may include metadataand/or other information (701). Referring now to FIG. 8, an exampleDiscoverer WTRU request procedure is illustrated. As part of theDiscoverer WTRU request procedure, the Discoverer (H)ProSe function mayacquire the metadata together with allocated ProSe query and responsecodes in a Discovery response message from the Discoveree (H)ProSefunction (801). The Discoverer (H)ProSe function may store the acquiredmetadata in storage.

Referring now to FIG. 9, an example match report procedure isillustrated. As part of the example match report procedure, theDiscoverer WTRU may send to the Discoverer (H)ProSe function a matchreport message (901) including a metadata flag (which metadata flag isincluded to signal that the Discoverer WTRU desires to receive thestored metadata). The Discoverer (H)ProSe function may extract themetadata from storage (903). The Discoverer (H)ProSe function may sendthe extracted metadata to the Discoverer WTRU in a match reportacknowledgement message (905).

Example Metadata Transfers to Discoveree WTRU

Metadata Flag in Discovery Request/Response along withDiscoveree-to-Discoverer Direct Metadata Transfer

FIGS. 10 and 11 are message flow diagrams illustrating exampleprocedures for use in connection with metadata transfer that may becarried out via Discoveree WTRU request procedure, Discoveree WTRUrequest procedure and direct-communication procedure phases of a ProSedirect discovery procedure. FIG. 10 illustrates example Discoveree WTRUrequest procedure. As part of the Discoveree WTRU request procedure, aDiscoveree WTRU may send to a Discoveree (H)ProSe function a discoveryrequest message that may include a metadata flag so as to signal thatthe Discoveree WTRU desires to receive metadata from a Discoverer WTRU(1001). Referring now to FIG. 11, an example Discoverer discoveryrequest procedure is illustrated. As part of the Discoverer discoveryrequest procedure, the Discoverer (H)ProSe function may receive from theDiscoveree (H)ProSe function a Discovery response message including themetadata flag together with allocated ProSe query and ProSe responsecodes (1101). The Discoverer WTRU may receive from the Discoverer(H)ProSe function a Discovery response message including the metadataflag and the ProSe query code (1103). Recognizing the metadata flag as aDiscoveree request for metadata, the Discoverer WTRU can proceed withappending or otherwise including the metadata in a discovery messagewhile announcing the ProSe query code over the air (1105).

Because the WTRUs may continue to announce their codes prior to expiryof their corresponding validity timers, the foregoing procedure offersthe flexibility of allowing the Discoverer WTRU to dynamically revise,update, replace, delete, remove, etc. the metadata at any time.Additionally, the Discoveree WTRU may decide (at some point) that itdoes not desire to continue acquiring metadata. To effect this, theDiscoveree WTRU may not include the metadata flag in further discoverymessages. Alternatively, the Discoveree WTRU may set the metadata flagto a value indicating a desire not to acquire the metadata.

Example Metadata Flag in Discovery Request to ProSe Functions and MatchReport Metadata Forwarding Procedures

FIGS. 10, 12 and 13 are message flow diagrams illustrating exampleprocedures for use in connection with metadata transfer that may becarried out via Discoveree WTRU request procedure, Discoveree WTRUrequest procedure and direct-communication procedure phases of a ProSedirect discovery procedure. Referring again to FIG. 10, as part of theDiscoveree WTRU request procedure, a Discoveree WTRU may send to aDiscoveree (H)ProSe function a discovery request message that mayinclude a metadata flag so as to signal that the Discoveree WTRU desiresto receive metadata from a Discoverer WTRU (1001). FIG. 12 illustratesan example Discoverer discovery request procedure. As part of theDiscoverer discovery request procedure, the Discoverer (H)ProSe functionmay receive from the Discoveree (H)ProSe function a Discovery responsemessage including the metadata flag together with allocated ProSe queryand ProSe response codes (1201). The metadata flag remains intact inDiscoverer (H)ProSe function. This way, when the Discoverer WTRU sendsthe metadata in a match report message to the Discoverer (H)ProSefunction (1301, FIG. 13), the Discoverer (H)ProSe function may check forthe presence of the metadata flag, and if present, the metadata may beextracted at the Discoverer (H)ProSe function (1303, FIG. 13). TheDiscoverer (H)ProSe function, thereafter, may pass the match reportinformation including the metadata with the Discoveree (H)ProSe function(1305. FIG. 13), which in turn, may push or otherwise provide themetadata to the Discoveree (1307, FIG. 13).

Discoveree-to-Discoverer Direct Metadata Flag Transfer and Match ReportInformation Forward

FIGS. 14 and 15 are message flow diagrams illustrating exampleprocedures for use in connection with metadata transfer that may becarried out via Discoveree WTRU request procedure, Discoveree WTRUrequest procedure and direct-communication procedure phases of a ProSedirect discovery procedure. FIG. 14 illustrates a direct-communicationprocedure. As part of the direct-communication procedure, a DiscovereeWTRU may send over the air a discovery message (e.g., a PC5 discoverymessage) including a metadata flag along with a ProSe response code(1401). When the Discoverer WTRU monitors for the ProSe response codeusing its discovery filter and notices the metadata flag, the DiscovererWTRU can then decide to include metadata information in a match reportmessage to the Discoverer (H)ProSe function (1501, FIG. 15). TheDiscoverer (H)ProSe function may store the metadata (1503). TheDiscoverer (H)ProSe function may push or otherwise send the metadata tothe Discoveree (H)ProSe function (1505), which in turn, may push orotherwise provide the metadata to the Discoveree (1507).

Multi-Level Metadata Classification and Indication

One possible refinement is to classify metadata into variouslevels/classes (e.g., ‘short’ versus ‘long’ metadata in case of twoMetadata levels/classes) depending on information type. This way, arequesting WTRU may pledge for a specific metadata level/class accordingto its needs. To facilitate this, an application server may definedifferent metadata levels/classes together with their correspondingcompositions (i.e., which metadata information type or component belongsto which metadata level/class) and possibly represent thoseclasses/levels with different indices (e.g., 1 bit to distinguishbetween ‘short’ and ‘long’ metadata). In a simple case of two metadatalevels/classes, the metadata information types or components may besorted according to (and among) the ‘short’ and ‘long’ metadataclasses/levels.

A WTRU may learn the metadata classification from the application serverover PC1 via application level signaling. After an application client atthe WTRU becomes acquainted with the metadata classification, anapplication layer in WTRU can know (or determine) which metadatalevel/class it wants to obtain, and may pass an associated index orother indicator of that desired metadata level/class(“metadata-level/class indicator”) to a ProSe layer in the WTRU. TheProSe protocol may then signal and append or otherwise combine themetadata-level/class indicator to the metadata flag so that only therequested metadata level/class is fetched from a target WTRU. In otherwords, the requesting WTRU may include metadata-level/class indicatoralong with the metadata flag so as to specify what level or granularityof metadata it is interested in obtaining. When the peer WTRU realizesthat the metadata-level/class indicator is for a specific metadatalevel/class, the ProSe layer at that WTRU may check with the applicationclient to extract the appropriate information pertaining to that leveland send such information back. Advantageously, this multi-levelmetadata approach may be applicable to all metadata transfers describeherein, regardless of whether the requesting WTRU is a Discoverer or aDiscoveree.

Example ProSe Code Application Suffix for Model B Discovery

Allocation of application Level suffix in Model B discovery may bedifferent from the current Model A procedure because ProSe codes areannounced by both Discoveree and Discoverer. The ProSe code suffix mayalso be announced by both a Discoveree and a Discoverer. The Discoverermay announce ProSe query code with suffix resulting in a ProSe responsecode with suffix from the Discoveree.

In Model B application controlled discovery procedure, each of theDiscoverer ProSe function and the Discoveree ProSe function may obtainmasks for ProSe code suffixes from the ProSe App server. The DiscovereeProSe function may receive a pool of ProSe code suffixes (“ProSe codesuffix pool”) directly from the ProSe application server. The DiscovererProSe function may receive the ProSe code suffix pool from theDiscoveree ProSe function.

Discoveree Request Procedure

FIG. 16 is a message flow diagram illustrating a Discoveree discoveryrequest procedure for application controlled suffix extension. Forsimplicity of exposition, the procedure of FIG. 16 is described withreference to the ProSe architecture of FIG. 2. The example procedure ofFIG. 16 may be carried out in other architectures, as well.

Prior to 1605 b, a ProSe App server may allocate a ProSe code suffixpool along with ProSe Mask(s) for monitoring for one or more of theProSe code suffixes. The ProSe code Prefix (allocated by the ProSefunction) and ProSe code suffix pool may be sent to the Discoveree. Ifthe ProSe Mask(s) are allocated by the ProSe App server, discoveryfilter(s) sent to the Discoveree may also include the ProSe Mask(s).

After receiving configuration information, a WTRU may send a discoveryrequest for Model B discovery with application controlled extension byspecifying the same in a discovery type field include in the discoveryrequest message (1603). The discovery request message may also include anew application level container that includes information correspondingto the ProSe code suffix (e.g., user information, group informationetc.).

The Discoveree ProSe function may authorize the request with an HSS(1605). At ref. 1605 a, Discoveree ProSe function may perform ProSe Appserver authorization, including sending an authorization request messagethat may include the new application level container. The authorizationrequest message may also include an allowed suffix number parameter.This allowed suffix number parameter may assist the ProSe App server tobuild the ProSe code suffix and may be set by the ProSe function basedon operator policy. After receiving this information, the ProSe Appserver may send an authorization response message that may include theProSe code suffix pool and masks for ProSe code suffixes (1605 b). Thesuffix masks may be used by the ProSe function to provide to theDiscoveree discovery filters for monitoring the ProSe query code withsuffix extension.

The ProSe response code and ProSe code suffix pool is sent to theDiscoveree, along with the discovery filters (which may include mask(s)for ProSe Suffix) (1611). In a roaming scenario (i.e., the Discoveree isregistered in a VPLMN), an Announce Authorization procedure may becarried with a Discoveree ProSe function of the VPLMN (“Discoveree(V)ProSe function”). During the Announce Authorization procedure, theDiscoveree (H)ProSe function may send to the Discoveree (V)ProSefunction an Announce Authorization message including the ProSe codesuffix pool.

Example Discoverer UE Request Procedure

FIG. 17 is a message flow diagram illustrating a Discoverer discoveryrequest procedure. For simplicity of exposition, the procedure of FIG.17 is described with reference to the ProSe architecture of FIG. 2. Theexample procedure of FIG. 17 may be carried out in other architectures,as well.

A Discoverer ProSe function may obtain ProSe code suffix mask(s) from aProSe App server during an application authorization stage if suffixinformation is included in the request message. Since in model Bdiscovery, codes are allocated by the Discoveree ProSe function, theProSe code suffix may be obtained by a Discoverer ProSe function asdescribed below. Both ProSe suffix code and ProSe suffix mask(s) may beused by the ProSe function to create discovery filter(s) sent to theWTRU in the Discovery response message.

As described above, in Model B application controlled discoveryprocedure, the Discoverer ProSe function and the Discoveree ProSefunction obtain the masks for the suffixes from the ProSe App server.The Discoveree ProSe function may receive the ProSe code suffix pooldirectly from the ProSe App server, and the Discoverer ProSe functionmay receive the ProSe code suffix pool from the Discoveree ProSefunction.

The Discoveree WTRU may specify “Model B discovery with applicationcontrolled extension” in the Discovery Type field of the DiscoveryRequest message (1701). The application level container may includeinformation related to ProSe suffix code.

After receiving configuration information, the Discoveree WTRU may senda discovery request for Model B discovery with application controlledextension by specifying the same in a discovery type field include inthe discovery request message (1701). The discovery request message mayalso include a new application level container that includes informationcorresponding to the ProSe code suffix (e.g., user information, groupinformation etc.).

This request may be authorized by an HSS and the ProSe App by theDiscoveree (H)ProSe function. The Authorization request message to theProSe App server may include information corresponding to theapplication suffix, and the application server may include ProSe Mask(s)for suffix code in an Authorization response message. Note that ProSeApp server does not include ProSe Suffix codes (as in the case of aDiscoveree request) because allowed suffix number parameter is notincluded in the Authorization request message.

If the Discoverer ProSe function and the Discoveree ProSe function aredifferent, a discovery Request may be sent to the Discoveree ProSefunction (1703). After an optional application authorization (1705 a,1705 b), the Discoveree ProSe function may responds with a ProSe querycode, a ProSe response code and a ProSe code suffix pool. The DiscovereeProSe function may have earlier received the ProSe code suffix pool(1705 a).

The ProSe response code and ProSe code suffix pool may be sent to theDiscoveree WTRU (1717) along with discovery filters (which may includemask(s) for ProSe Suffix received by the ProSe function (1705 b). In aroaming scenario (i.e., the Discoveree WTRU is registered in a VPLMN),an Announce Authorization procedure may be carried with a Discoveree(V)ProSe function. During the Announce Authorization procedure, theDiscoveree (H)ProSe function may send to the Discoveree (V)ProSefunction an Announce Authorization message including the ProSe codesuffix pool.

Example ProSe Code Validity Timer Management Procedures and Architecture

A Discoverer (or other monitoring WTRU) may need to refresh its matchreports notwithstanding that validity timers for ProSe codes associatedwith such reports have not expired. Various reasons exist for refreshingmatch reports, including, for example, security requirements (e.g., toprevent or at least limit replay attacks). To facilitate this, in oneembodiment, a match report refresh timer is provided to the Discoverer(or other monitoring WTRU) during a direct discovery procedure. Anexample of the match report refresh timer may be found in 3GPP TechnicalDocument No. C1-151342, which is incorporated herein by reference.

The match report refresh timer may be used the Discoverer (or othermonitoring WTRU) to determine whether to send a new match report requestmessage to a ProSe function to validate the ProSe code (ProSeapplication code) it previously received. If, for example, the matchreport refresh timer expires prior to expiry of the validity timer ofsuch ProSe code, then the Discoverer (or other monitoring WTRU) maydetermine to send, and in turn, may send the new match report requestmessage to the ProSe function to initiate (i) a refresh of thecorresponding match report or (ii) a new match report procedure.

In some instances, the ProSe function may reject the new match reportrequest for various reasons, such as invalid MIC value, wrong UTC timer,etc. In such instances, the ProSe function may send a match reportreject message to the Discoverer (or other monitoring WTRU). Possibleconsequences of rejecting the new match report request are (i) thevalidity timer may continue to run at the Discoverer (or othermonitoring WTRU) and (ii) upper layers in the Discoverer (or othermonitoring WTRU) may assume that the ProSe code (ProSe application code)is still valid.

The Discoverer (or other monitoring WTRU) may stop the validity timerand/or inform the upper layers that the ProSe code (ProSe applicationcode) is no longer valid responsive to a match report reject messagefrom the ProSe function. The Discoverer (or other monitoring WTRU) maysend a new match report request or discovery request for monitoringthereafter, e.g., at a next match event.

As an alternative, the Discoverer (or other monitoring WTRU) may sendadditional match report requests up to some number N times (e.g., 3 or 5retries). If none of the additional match report request are successful(or all are rejected) prior to expiry of the validity timer, theDiscoverer (or other monitoring WTRU) may stop validity timer/or andinform the upper layers that the ProSe code (ProSe application code) isno longer valid.

Conclusion

Although features and elements are provided above in particularcombinations, one of ordinary skill in the art will appreciate that eachfeature or element can be used alone or in any combination with theother features and elements. The present disclosure is not to be limitedin terms of the particular embodiments described in this application,which are intended as illustrations of various aspects. Manymodifications and variations may be made without departing from itsspirit and scope, as will be apparent to those skilled in the art. Noelement, act, or instruction used in the description of the presentapplication should be construed as critical or essential to theinvention unless explicitly provided as such. Functionally equivalentmethods and apparatuses within the scope of the disclosure, in additionto those enumerated herein, will be apparent to those skilled in the artfrom the foregoing descriptions. Such modifications and variations areintended to fall within the scope of the appended claims. The presentdisclosure is to be limited only by the terms of the appended claims,along with the full scope of equivalents to which such claims areentitled. It is to be understood that this disclosure is not limited toparticular methods or systems.

It is also to be understood that the terminology used herein is for thepurpose of describing particular embodiments only, and is not intendedto be limiting. As used herein, the term “video” may mean any of asnapshot, single image and/or multiple images displayed over a timebasis. As another example, when referred to herein, the terms “userequipment” and its abbreviation “UE” may mean (i) a wireless transmitand/or receive unit (WTRU), such as described supra; (ii) any of anumber of embodiments of a WTRU, such as described supra; (iii) awireless-capable and/or wired-capable (e.g., tetherable) deviceconfigured with, inter alia, some or all structures and functionality ofa WTRU, such as described supra; (iii) a wireless-capable and/orwired-capable device configured with less than all structures andfunctionality of a WTRU, such as described supra; or (iv) the like.Details of an example WTRU, which may be representative of any UErecited herein, are provided above with respect to FIGS. 1A-1E.

In addition, the methods provided herein may be implemented in acomputer program, software, or firmware incorporated in acomputer-readable medium for execution by a computer or processor.Examples of computer-readable media include electronic signals(transmitted over wired or wireless connections) and computer-readablestorage media. Examples of computer-readable storage media include, butare not limited to, a read only memory (ROM), a random access memory(RAM), a register, cache memory, semiconductor memory devices, magneticmedia such as internal hard disks and removable disks, magneto-opticalmedia, and optical media such as CD-ROM disks, and digital versatiledisks (DVDs). A processor in association with software may be used toimplement a radio frequency transceiver for use in a WTRU, UE, terminal,base station, RNC, or any host computer.

Variations of the method, apparatus and system provided above arepossible without departing from the scope of the invention. In view ofthe wide variety of embodiments that can be applied, it should beunderstood that the illustrated embodiments are examples only, andshould not be taken as limiting the scope of the following claims. Forinstance, the embodiments provided herein include handheld devices,which may include or be utilized with any appropriate voltage source,such as a battery and the like, providing any appropriate voltage.

Moreover, in the embodiments provided above, processing platforms,computing systems, controllers, and other devices containing processorsare noted. These devices may contain at least one Central ProcessingUnit (CPU″) and memory. In accordance with the practices of personsskilled in the art of computer programming, reference to acts andsymbolic representations of operations or instructions may be performedby the various CPUs and memories. Such acts and operations orinstructions may be referred to as being “executed,” “computer executed”or “CPU executed.”

One of ordinary skill in the art will appreciate that the acts andsymbolically represented operations or instructions include themanipulation of electrical signals by the CPU. An electrical systemrepresents data bits that can cause a resulting transformation orreduction of the electrical signals and the maintenance of data bits atmemory locations in a memory system to thereby reconfigure or otherwisealter the CPU's operation, as well as other processing of signals. Thememory locations where data bits are maintained are physical locationsthat have particular electrical, magnetic, optical, or organicproperties corresponding to or representative of the data bits. Itshould be understood that the embodiments are not limited to theabove-mentioned platforms or CPUs and that other platforms and CPUs maysupport the provided methods.

The data bits may also be maintained on a computer readable mediumincluding magnetic disks, optical disks, and any other volatile (e.g.,Random Access Memory (RAM″)) or non-volatile (e.g., Read-Only Memory(ROM″)) mass storage system readable by the CPU. The computer readablemedium may include cooperating or interconnected computer readablemedium, which exist exclusively on the processing system or aredistributed among multiple interconnected processing systems that may belocal or remote to the processing system. It should be understood thatthe embodiments are not limited to the above-mentioned memories and thatother platforms and memories may support the provided methods.

In an illustrative embodiment, any of the operations, processes, etc.described herein may be implemented as computer-readable instructionsstored on a computer-readable medium. The computer-readable instructionsmay be executed by a processor of a mobile unit, a network element,and/or any other computing device.

There is little distinction left between hardware and softwareimplementations of aspects of systems. The use of hardware or softwareis generally (but not always, in that in certain contexts the choicebetween hardware and software may become significant) a design choicerepresenting cost vs. efficiency tradeoffs. There may be variousvehicles by which processes and/or systems and/or other technologiesdescribed herein may be effected (e.g., hardware, software, and/orfirmware), and the preferred vehicle may vary with the context in whichthe processes and/or systems and/or other technologies are deployed. Forexample, if an implementer determines that speed and accuracy areparamount, the implementer may opt for a mainly hardware and/or firmwarevehicle. If flexibility is paramount, the implementer may opt for amainly software implementation. Alternatively, the implementer may optfor some combination of hardware, software, and/or firmware.

The foregoing detailed description has set forth various embodiments ofthe devices and/or processes via the use of block diagrams, flowcharts,and/or examples. Insofar as such block diagrams, flowcharts, and/orexamples contain one or more functions and/or operations, it will beunderstood by those within the art that each function and/or operationwithin such block diagrams, flowcharts, or examples may be implemented,individually and/or collectively, by a wide range of hardware, software,firmware, or virtually any combination thereof. In an embodiment,several portions of the subject matter described herein may beimplemented via Application Specific Integrated Circuits (ASICs), FieldProgrammable Gate Arrays (FPGAs), digital signal processors (DSPs),and/or other integrated formats. However, those skilled in the art willrecognize that some aspects of the embodiments disclosed herein, inwhole or in part, may be equivalently implemented in integratedcircuits, as one or more computer programs running on one or morecomputers (e.g., as one or more programs running on one or more computersystems), as one or more programs running on one or more processors(e.g., as one or more programs running on one or more microprocessors),as firmware, or as virtually any combination thereof, and that designingthe circuitry and/or writing the code for the software and or firmwarewould be well within the skill of one of skill in the art in light ofthis disclosure. In addition, those skilled in the art will appreciatethat the mechanisms of the subject matter described herein may bedistributed as a program product in a variety of forms, and that anillustrative embodiment of the subject matter described herein appliesregardless of the particular type of signal bearing medium used toactually carry out the distribution. Examples of a signal bearing mediuminclude, but are not limited to, the following: a recordable type mediumsuch as a floppy disk, a hard disk drive, a CD, a DVD, a digital tape, acomputer memory, etc., and a transmission type medium such as a digitaland/or an analog communication medium (e.g., a fiber optic cable, awaveguide, a wired communications link, a wireless communication link,etc.).

Those skilled in the art will recognize that it is common within the artto describe devices and/or processes in the fashion set forth herein,and thereafter use engineering practices to integrate such describeddevices and/or processes into data processing systems. That is, at leasta portion of the devices and/or processes described herein may beintegrated into a data processing system via a reasonable amount ofexperimentation. Those having skill in the art will recognize that atypical data processing system may generally include one or more of asystem unit housing, a video display device, a memory such as volatileand non-volatile memory, processors such as microprocessors and digitalsignal processors, computational entities such as operating systems,drivers, graphical user interfaces, and applications programs, one ormore interaction devices, such as a touch pad or screen, and/or controlsystems including feedback loops and control motors (e.g., feedback forsensing position and/or velocity, control motors for moving and/oradjusting components and/or quantities). A typical data processingsystem may be implemented utilizing any suitable commercially availablecomponents, such as those typically found in datacomputing/communication and/or network computing/communication systems.

The herein described subject matter sometimes illustrates differentcomponents contained within, or connected with, different othercomponents. It is to be understood that such depicted architectures aremerely examples, and that in fact many other architectures may beimplemented which achieve the same functionality. In a conceptual sense,any arrangement of components to achieve the same functionality iseffectively “associated” such that the desired functionality may beachieved. Hence, any two components herein combined to achieve aparticular functionality may be seen as “associated with” each othersuch that the desired functionality is achieved, irrespective ofarchitectures or intermedial components. Likewise, any two components soassociated may also be viewed as being “operably connected”, or“operably coupled”, to each other to achieve the desired functionality,and any two components capable of being so associated may also be viewedas being “operably couplable” to each other to achieve the desiredfunctionality. Specific examples of operably couplable include but arenot limited to physically mateable and/or physically interactingcomponents and/or wirelessly interactable and/or wirelessly interactingcomponents and/or logically interacting and/or logically interactablecomponents.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations may be expressly set forth herein for sakeof clarity.

It will be understood by those within the art that, in general, termsused herein, and especially in the appended claims (e.g., bodies of theappended claims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”etc.). It will be further understood by those within the art that if aspecific number of an introduced claim recitation is intended, such anintent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, where only oneitem is intended, the term “single” or similar language may be used. Asan aid to understanding, the following appended claims and/or thedescriptions herein may contain usage of the introductory phrases “atleast one” and “one or more” to introduce claim recitations. However,the use of such phrases should not be construed to imply that theintroduction of a claim recitation by the indefinite articles “a” or“an” limits any particular claim containing such introduced claimrecitation to embodiments containing only one such recitation, even whenthe same claim includes the introductory phrases “one or more” or “atleast one” and indefinite articles such as “a” or “an” (e.g., “a” and/or“an” should be interpreted to mean “at least one” or “one or more”). Thesame holds true for the use of definite articles used to introduce claimrecitations. In addition, even if a specific number of an introducedclaim recitation is explicitly recited, those skilled in the art willrecognize that such recitation should be interpreted to mean at leastthe recited number (e.g., the bare recitation of “two recitations,”without other modifiers, means at least two recitations, or two or morerecitations). Furthermore, in those instances where a conventionanalogous to “at least one of A, B, and C, etc.” is used, in generalsuch a construction is intended in the sense one having skill in the artwould understand the convention (e.g., “a system having at least one ofA, B, and C” would include but not be limited to systems that have Aalone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). In those instances where aconvention analogous to “at least one of A, B, or C, etc.” is used, ingeneral such a construction is intended in the sense one having skill inthe art would understand the convention (e.g., “a system having at leastone of A, B, or C” would include but not be limited to systems that haveA alone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). It will be furtherunderstood by those within the art that virtually any disjunctive wordand/or phrase presenting two or more alternative terms, whether in thedescription, claims, or drawings, should be understood to contemplatethe possibilities of including one of the terms, either of the terms, orboth terms. For example, the phrase “A or B” will be understood toinclude the possibilities of “A” or “B” or “A and B.” Further, the terms“any of” followed by a listing of a plurality of items and/or aplurality of categories of items, as used herein, are intended toinclude “any of,” “any combination of,” “any multiple of,” and/or “anycombination of multiples of” the items and/or the categories of items,individually or in conjunction with other items and/or other categoriesof items. Moreover, as used herein, the term “set” is intended toinclude any number of items, including zero. Additionally, as usedherein, the term “number” is intended to include any number, includingzero.

In addition, where features or aspects of the disclosure are describedin terms of Markush groups, those skilled in the art will recognize thatthe disclosure is also thereby described in terms of any individualmember or subgroup of members of the Markush group.

As will be understood by one skilled in the art, for any and allpurposes, such as in terms of providing a written description, allranges disclosed herein also encompass any and all possible subrangesand combinations of subranges thereof. Any listed range can be easilyrecognized as sufficiently describing and enabling the same range beingbroken down into at least equal halves, thirds, quarters, fifths,tenths, etc. As a non-limiting example, each range discussed herein maybe readily broken down into a lower third, middle third and upper third,etc. As will also be understood by one skilled in the art all languagesuch as “up to,” “at least,” “greater than,” “less than,” and the likeincludes the number recited and refers to ranges which can besubsequently broken down into subranges as discussed above. Finally, aswill be understood by one skilled in the art, a range includes eachindividual member. Thus, for example, a group having 1-3 cells refers togroups having 1, 2, or 3 cells. Similarly, a group having 1-5 cellsrefers to groups having 1, 2, 3, 4, or 5 cells, and so forth.

Moreover, the claims should not be read as limited to the provided orderor elements unless stated to that effect. In addition, use of the terms“means for” in any claim is intended to invoke 35 U.S.C. §112, ¶6 ormeans-plus-function claim format, and any claim without the terms “meansfor” is not so intended.

What is claimed is:
 1. A method implemented in a first proximityservices (ProSe) function serving a discoverer user equipment (UE), themethod comprising: receiving, from the discoverer UE, a first discoveryrequest message including a ProSe application identifier and anindication indicating Model B discovery; transmitting, to a second ProSefunction configured to serve a discoveree UE, a second discovery requestmessage requesting a ProSe application code corresponding to the ProSeapplication identifier; determining that no valid ProSe application codecorresponding to the ProSe application identifier is available based onany of: not receiving a response to the second discovery requestmessage; not receiving any valid ProSe application code corresponding tothe ProSe application identifier in response to the second discoveryrequest message; and receiving, in response to the second discoveryrequest message, an indication indicating that no valid ProSeapplication code corresponding to the ProSe application identifier isavailable; and transmitting, to the discoverer UE, a reject-typediscovery response message.
 2. The method of claim 1, wherein thereject-type discovery response message comprises a causeindication/value.
 3. The method of claim 2, wherein the causeindication/value is an indication of “No valid Discovery Filters” or “Novalid ProSe code available”.
 4. The method of claim 1, wherein notreceiving a response to the second discovery request message comprisesnot timely receiving a response to the second discovery request message.5. The method of claim 1, wherein not receiving any valid ProSeapplication code corresponding to the ProSe application identifier inresponse to the second discovery request message comprises not timelyreceiving any valid ProSe application code corresponding to the ProSeapplication identifier in response to the second discovery requestmessage.
 6. The method of claim 1, wherein the first discovery requestmessage is a monitoring type discovery request message.
 7. A firstproximity services (ProSe) function configured to serve a discovereruser equipment (UE), the first ProSe function comprising circuitry,including a processor and instructions executable by the processor,configured to: receive, from the discoverer UE, a first discoveryrequest message including a ProSe application identifier and anindication indicating Model B discovery; transmit, to a second ProSefunction configured to serve a discoveree UE, a second discovery requestmessage requesting a ProSe application code corresponding to the ProSeapplication identifier; determine that no valid ProSe application codecorresponding to the ProSe application identifier is available based onany of: not receiving a response to the second discovery requestmessage; not receiving any valid ProSe application code corresponding tothe ProSe application identifier in response to the second discoveryrequest message; and receiving, in response to the second discoveryrequest message, an indication indicating that no valid ProSeapplication code corresponding to the ProSe application identifier isavailable; and transmit, to the discoverer UE, a reject-type discoveryresponse message.
 8. The first ProSe function of claim 7, wherein thereject-type discovery response message comprises a causeindication/value.
 9. The first ProSe function of claim 8, wherein thecause indication/value is an indication of “No valid Discovery Filters”or “No valid ProSe code available”.
 10. The first ProSe function ofclaim 7, wherein not receiving a response to the second discoveryrequest message comprises not timely receiving a response to the seconddiscovery request message.
 11. The first ProSe function of claim 7,wherein not receiving any valid ProSe application code corresponding tothe ProSe application identifier in response to the second discoveryrequest message comprises not timely receiving any valid ProSeapplication code corresponding to the ProSe application identifier inresponse to the second discovery request message.
 12. A methodimplemented in a wireless transmit/receive unit (WTRU) participating ina proximity services (ProSe) direct discovery procedure, the methodcomprising: sending a match report request message to a ProSe functionafter expiry of a match report refresh timer and prior to expiry of avalidity timer of a ProSe code; receiving a match report reject messagefrom the ProSe function; and stopping the validity timer responsive tothe match report reject message.
 13. The method of claim 12, furthercomprising: informing upper layers of the WTRU that the ProSe code is nolonger valid.
 14. The method of claim 12, wherein the match reportreject message comprises a cause value indicating an invalid MIC.
 15. Awireless transmit/receive unit (WTRU) configured to participate in aproximity services (ProSe) direct discovery procedure, the WTRUcomprising a transmitter, a receiver, a processor, a match reportrefresh timer and a validity timer of a proximity services (ProSe) code,wherein: the processor in combination with the transmitter is configuredto send a match report request message to a ProSe function after expiryof the match report refresh timer and prior to expiry of the validitytimer of a ProSe code; the receiver is configured to receive a matchreport reject message from the ProSe function; and the processor isconfigured to stop the validity timer responsive to the match reportreject message.
 16. The WTRU of claim 15, wherein the processor isconfigured to inform upper layers of the WTRU that the ProSe code is nolonger valid.
 17. The WTRU of claim 15, wherein the match report rejectmessage comprises a cause value indicating an invalid MIC.
 18. A methodimplemented in a proximity services (ProSe) function, the methodcomprising: receiving a match report request message from a wirelesstransmit/receive unit (WTRU) after expiry of a match report refreshtimer and prior to expiry of a validity timer of a ProSe code; andtransmitting a match report reject message to the WTRU.
 19. The methodof claim 18, wherein the match report reject message comprises a causevalue indicating an invalid MIC.
 20. A proximity services (ProSe)function comprising circuitry, including a processor and instructionsexecutable by the processor, configured to: receive a match reportrequest message from a wireless transmit/receive unit (WTRU) afterexpiry of a match report refresh timer and prior to expiry of a validitytimer of a ProSe code; and transmit a match report reject message to theWTRU.
 21. The ProSe function of claim 20, wherein the match reportreject message comprises a cause value indicating an invalid MIC.
 22. Amethod implemented in a first proximity services (ProSe) functionconfigured to serve a discoveree user equipment (UE), the methodcomprising: receiving, from a second ProSe function engaged in Model Bdiscovery with a discoverer UE, a discovery request message requesting aProSe application code corresponding to a ProSe application identifierassociated with the discoverer UE; determining whether a valid ProSeapplication code corresponding to the ProSe application identifier isavailable to the first ProSe function; and on condition that a validProSe application code corresponding to the ProSe application identifieris not available to the first ProSe function: not responding to thediscovery request message; or transmitting, to the second ProSefunction, a response to the discovery request message including anindication indicating that no valid ProSe application code correspondingto the ProSe application identifier is available.
 23. The method ofclaim 22, further comprising: transmitting a second reject-typediscovery response message to a WTRU.
 24. The method of claim 23,wherein the second reject-type discovery response message comprises acause indication/value.
 25. The method of claim 24, wherein the causeindication/value is an indication of “No valid Discovery Filters” or “Novalid ProSe code available”.
 26. The method of claim 22, wherein theindication is a lack of any valid ProSe application code correspondingto the ProSe application identifier being included in the response. 27.The method of claim 22, wherein the indication is an explicit indicationindicating that no valid ProSe application code corresponding to theProSe application identifier is available.
 28. The method of claim 22,wherein the discovery request message is a monitoring type discoveryrequest message.
 29. The first ProSe function of claim 22, wherein thediscovery request message is a monitoring type discovery requestmessage.
 30. A first proximity services (ProSe) function configured toserve a discoveree user equipment (UE), the first ProSe functioncomprising circuitry, including a processor and instructions executableby the processor, configured to: receive, from a second ProSe functionengaged in Model B discovery with a discoverer UE, a discovery requestmessage requesting a ProSe application code corresponding to a ProSeapplication identifier associated with the discoverer UE; determinewhether a valid ProSe application code corresponding to the ProSeapplication identifier is available to the first ProSe function; and oncondition that a valid ProSe application code corresponding to the ProSeapplication identifier is not available to the first ProSe function: notrespond to the discovery request message; or transmit, to the secondProSe function, a response to the discovery request message including anindication indicating that no valid ProSe application code correspondingto the ProSe application identifier is available.
 31. The first ProSefunction of claim 30, wherein the response is a reject-type discoveryresponse message.
 32. The first ProSe function of claim 31, wherein thereject-type discovery response message comprises a causeindication/value.
 33. The first ProSe function of claim 32, wherein thecause indication/value is an indication of “No valid Discovery Filters”or “No valid ProSe code available”.
 34. The first ProSe function ofclaim 30, wherein the discovery request message is a monitoring typediscovery request message.
 35. The first ProSe function of claim 30,wherein the indication is a lack of any valid ProSe application codecorresponding to the ProSe application identifier being included in theresponse.
 36. The first ProSe function of claim 30, wherein theindication is an explicit indication indicating that no valid ProSeapplication code corresponding to the ProSe application identifier isavailable.